A hibiscus bush can make a lovely addition to any garden, but there are several basic requirements that must be met in order for the plant to bloom and thrive. Planting in the proper location is vital if you want large, fragrant flowers. Sun, soil, water, fertiliser and mulch also play a crucial part in the performance of the hibiscus bush. Follow these guidelines and you'll have gorgeous flowers for years to come.
Plant the hibiscus bush in an area of full sun, and sheltered from harsh or cold winds. Hibiscus will grow in areas of partial shade, but will not bloom as abundantly. Plant the hibiscus bush in its own bed, for best results, so it does not have to compete for light, water and food.
Provide the hibiscus bush with sandy, well-drained soil. It cannot tolerate standing water around the roots. Enrich the soil with compost and organic material, such as peat moss, by working it into the soil thoroughly. If the area of planting does not appear well-drained, raise the bed by 25 to 40 cm, and fill it with sandy, compost-enriched soil.
Prune a hibiscus bush before new growth of the season begins, but after the last expected frost in your area. This time will vary, depending on location, but is usually in early spring. Prune enough of the hibiscus bush to keep it at about 2 metres tall when fully grown. Prune back about a third of the growth until the hibiscus bush reaches this height.
Fertilise a hibiscus bush after pruning, when new shoots begin to appear, at least three weeks after pruning. Use a water-soluble plant fertiliser that contains a large amount of potassium, very little phosphorous and moderate nitrogen. Combine the fertiliser with water in a container, and apply directly to the soil around the plant. Repeat fertilisation once every three or four weeks, throughout the spring and summer, as long as there is new growth.
Water your hibiscus bush thoroughly, soaking the ground each time. Allow the ground to dry out completely in between waterings. During hot summers, watering may be necessary two to three times per week. In cooler conditions, once per week may be sufficient. Stick your finger in the ground around the plant to the second knuckle. If it is dry, water the hibiscus bush thoroughly.
Mulch your hibiscus bush to keep in moisture and prevent weeds. Add mulch up to 7.5 cm from where the trunk of the bush leaves the ground. Do not allow the mulch to come in contact with the trunk, as this can cause the development of fungus or root rot.
The minimum sun requirement for a hibiscus bush is four hours per day. If you cannot place them in a location that receives at least this much full sun, they may not bloom, or fail to thrive completely.
Any type of mulch may be used for a hibiscus bush, although pine bark and straw are commonly used.
Do not fertilise a hibiscus bush when the soil is dry. Make sure it is moist before application, or you risk burning the roots.